The present invention relates to a fuel atomizer for automobiles which can cope with fuel supply for multi-fuel and multi-point injection.
Heretofore, fuel supply devices for automobiles have been broadly classified into the two sorts of a carburettor and a fuel injector. The former adopts a continuous fuel measuring system, while the latter an intermittent fuel measuring system, and they are installed on multicylinder engines.
With the fuel supply devices, however, the diameters of fuel liquid drops generated are not uniform and very small. Therefore, the uniform distribution of fuel to the respective cylinders of the multicylinder engine cannot be achieved, and fuel to be supplied to the respective cylinders becomes ununiform. The resulting ununiform fuel causes a stable combustion and induces the degradations of an exhaust purification efficiency and a combustion efficiency, which form factors for increasing fuel consumption and a harmful exhaust level. Moreover, in using various sorts of fuel and lowering the grade of fuel recently, the situations cannot be coped with only the fuel supply system based on both the above systems, and a fuel supply system having novel atomization means is eagerly requested.
Meanwhile, from the standpoint of purchasing an automobile, it is desirable that the engine power is high and that the automobile is inexpensive. In this regard, the fuel injector has injection valves for the respective cylinders and employs a suction inertia utilizing arrangement in which a suction pipe is lengthened. Therefore, this system is effective from the viewpoint of enhancing the power, but unfavorably a high cost is incurred on account of a complicated structure. On the other hand, the carburettor system is a system in which fuel measuring portions are concentrated on one point. Although it is simple in arrangement and low in cost, it has the problem that the structure of a suction pipe has a shape incapable of utilizing suction inertia, so the enhancement of power cannot be expected.
For these reasons, there has recently been proposed the technique of atomizing fuel by the use of the ring vibrator of an ultrasonic vibration system as described in the official gazette of Japanese Laid-open Patent Application No. 53-140415. With the ring vibrator, however, the fuel must be concentrated on one point. This leads to the problems that the technique as it is cannot be applied to a multi-point fuel injection type engine, the scope of use thereof being restricted to carburettor type and single-point fuel injection type engines, and that the enhancement of power cannot be expected.